1. Field of the Invention
The present invention relates to a system for serially feeding pieces of stationery such as envelopes to a printing station of a conventional printing machine such as a typewriter, and for removing pieces of printed stationery from the printing station.
2. Prior Art
There has long been a need for a reliable system to automatically serially feed pieces of stationery such as envelopes to and from a printing station of a printer such as a typewriter. With the advent of automatic typewriters and other types of programmable printing equipment which can operate without human attendance, the need for a reliable stationary feeder system has been accentuated.
In an effort to satisfy this need, several proposals have been made. One proposal is to utilize continuous-form stationery rather than discrete pieces of stationery, whereby an uninterrupted web of stationery is fed around a platen roll of a printer. This proposal has suffered from several drawbacks including the increased costs of continuous-form stationary, and the form-letter appearance of such stationery which often results in advertising mailings being readily detected and discarded by recipients.
Another proposal has been to provide a feeding unit in the form of an appliance which is positioned adjacent to a platen roll of a printer for serially introducing envelopes to the printer at one side of the platen roll, and for removing printed envelopes from the other side of the platen roll. This proposal lacks a positive-feed transport system for reliably conveying envelopes around the platen roll for precise positioning at a printing station, whereby it is not uncommon for envelopes to misfeed or fail to feed around the platen roll of the printer.